Starting device for mercury-vapor apparatus.



J. C. POLE.

STARTING DEVICE FOR MERCURY VAPOR APPARATUS.

APPLICATION FILED NOV. 14. 1912.

Patented Oct. 26, 1915.

BY A M a! ATTORNEY WITNESSES 7/ /4 2 1 I I UNITED srarnsrarnnr ICE,

JOSEPH C. POLE, OF NEW YORK, N. Y., ASSIGNOR TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

STARTING DEVICE FOR MERCURY-VAPOR APPARATUS.

Application filed November 14, 1912.

To all whom it may concern:

Be it known that I, JOSEPH C. POLE, a subject of the Emperor of Austria-Hungary, and resident of New York, county of New York, State of New York, have invented certain new and useful Improvements in Starting Devices for Mercury-Vapor Apparatus, of which the following is a specification.

The subject of the present invention is an apparatus for automatically starting into operation a mercury vapor rectifier adapted to supply one or more translating devices.

The details of the apparatus will be fully set forth in connection with the accompanying drawings in which- Figures 1 and 2 illustrate in detail, through front and side elevations respectively, a rectifier apparatus of the well known Cooper Hewitt type and the immediate connectlons thereof; while Fig. 3 shows the electrical connections utilized for such an apparatus when the translating devices are automatic direct current Cooper Hewitt lamps.

In Fig. 1 is shown at 1' the container of a mercury rectifier of the type specified and in Fig. 2 the same apparatus is illustrated in side elevation. In this rectifier the positive electrodes are shown at 2 and 3, the main mercury cathode at 4: and the mercury starting electrode at 5. The rectifier is supported upon a curved holder, 6, pivoted on a shaft, 7, which is mounted in bearings in a bracket, 8. lVith this arrangement the container, 1, can readily be tilted by turning the shaft, 7, and the electrodes 4 and 5 can be placed in or out of contact at will. It should be noted that the electrodes 4 and 5 are separated from each other during the period when the rectifier is not operating.

The direct means for tilting the rectifier for starting or stopping operation consists of a tilting lever, 9, rigidly connected to the shaft, 7, and having on one end an adjust able counter weight, 10, in combination with a solenoid, 13, and its plunger, 12, the latter being connected to the tilting lever, 9, through the medium of a spiral spring, 11. The plunger, 12, is preferably of laminated iron and it is adapted to move up and down in the solenoid, 13, which is wound on ahollow core, 14, and connected by means of the bracket, 15, to the panel, 60, supporting the whole rectifier structure. The core, 141,

Specification of Letters Patent.

Patented Oct. 26, 1915.

Serial No. 731,234.

is split in a plane normal to the winding of the solenoid so as to avoid heavy eddy currents.

The solenoid, 13, has two windings, as will be explained further on. In circuit with the said windings, one or both, is a small startmg resistance, 16, which in some instances is an essential feature and in others may be dispensed with. An automatic cut out for the rectifier is provided, the same consisting of a coil or solenoid, 18, an iron core, 19, a movable armature, 20, and a back stop or contact, 21. i

All the foregoing features are shown in greater or less detail in Figs. 1 and 2, but the circuits and connections are more clearly represented in Fig. 3 where the same are schematically shown in combination with a work circuit containing direct current Cooper Hewitt mercury vapor lamps appearing at 30, 31, 32, and 33.

The tube and the elements inclosed there in have all been described. In Fig. 3 I show an auto transformer having suitable connections through a switch, 37, with an alternating current source. The terminals of the transformer are placed at 23 and 21, the middle point being shown at In this figure, for the sake of showing the circuits more clearly, the coils of the solenoid, 13, are represented as distinct coils, 2G and 27, though it is to be understood that these coils are wound upon the same hollow core, 11, as described above. These two coils are wound in opposite directions, one end of each coil being connected to a point, 28, the other end of the coil, 26, being connected to the starting electrode 5 and the free end of the coil, 27, being connected by way of the starting resistance, 16, to one end of the solenoid, 18, of the automatic cut out. The opposite end of the coil, 18, is connected to the rectifier cathode, 4:. It will be observed that the circuits of only one of the direct current lamps, for instance, lamp 32. Here is indicated a magnetic coil, 34, an iron plunger, 35, and an automatic cut out, 36, the whole serving as an automatic tilting device for starting the operation of the lamp. The other lamps will generally be supplied with similar starting devices. A switch, 38, is also indicated for throwing the translating devices into circuit.

The operation of the rectifier is the following: The main switch, 37, and the switch, 38, one lamp being closed on the direct current side of the rectifier and the container of the rectifier being in its position of rest, wherein the mercury electrodes, 1 and 5, are separated, the alternating current will pass through one half, 24 and 25 of the transformer, 22, by way of the switch, 38, through the tilting magnets, and 30, the starting resistance, 16, the tilting coll, 27, the contacts, 20 and 21, back to 24. The solenoid, 27, being thus energized, will attract the iron plunger, 12, and thus will tilt the container, 1, until the mercury electrodes, 4 and 5, are brought into contact. At

this moment, the circuit of the other magnet, 26, of the tilting solenoid is closed and the alternating current can now pass from the transformer by way of the terminal, 24, through the carbon contacts, 20 and 21, the winding, 26, the mercury electrodes, 1 and 5, the solenoid, 18, of the automatic cut out, the lamps, 30 and 32, and the switch, 38, back to the neutral point, At the same time the lamps, 31 and 33, will be brought into operation through the direct connection of the latter with the consumption cir-' cuit of the rectifier.

As already mentioned, the coils, 26 and 27, are wound in opposite directions so that the magnetic flux of one winding is opposed to the fiux of the other winding. Similarly the ampere turns of the two coils are designed so that the magnetic flux of the winding, 27, where it passes the plunger, 12, is about equal to the magnetic flux driven through the plunger by the winding, 26. Accordingly, when the rectifier bulb is tilted and the two mercury electrodes brought together, one winding of the tilting solenoid will counteract the magnetic flux of the other and, the plunger, 12,- being de-magnetized, the rectifier bulb will by its own weight and by the effect of the counter weight, 10, fall back into its position of rest. Thereby the mercury electrodes. 4 and 5, are separated and the rectifier is started. However, should the interruption of the contact between 1 and 5 happen to take place at the wrong period of the alternating current phase (where 4 is an anode) and should the rectifier not start, then the play of the tilting solenoid, 13, will go on and keep on until the starting follows. Thereupon the direct rectified current, passing through the cathode, 4, and the solenoid, 18, of the cut out, 17, will lift the armature, 20, and interrupt the circuit of the tilting device.

Among the advantages of the tilting apparatus described are the following: The mechanical and electrical'parts of the tilting device are extremely simple,not requiring any other movable parts except the plunger and the tilting lever and requiring no automatic relays or cut outs with the exception of what would be used for a non-automatic rectifier. The tilting device having the electrical connections shown in Fig.

3 does not ,come into operation until or unless some load is put upon the direct current side of the rectifier. Consequently, it can not happen that the tilting device is kept operating when the main alternating current switch, 37', is closed while the switch, 38, remains open. Otherwise the rectifier would be kept tilting without being able to start, and the tilting device would not only be impaired or burned out, but the-continual breaking of the contact of the mercury electrodes, 4 and 5, would cause a needless strain on the insulation of the apparatus.

The alternating current in the solenoid is limited by the inductance of the solenoid and by the resistance and the inductance, as the case may be, of the direct current load, so that the starting resistance, 16, for the tilting device may generally be dispensed with. However, should any one desire to make the tilting device perfectly safe in the way of being able to withstand the starting current for a considerable length of time,

when, for example, the shaft, 7, in the bear-* ing, 8, sticks or when the container, 1, has lost its vacuum or for other like causes, it will, as a rule, be necessary to have the dimensions of the solenoid rather 'large. But this is disadvantageous from the electrical point of view. since the stray field of the magnets, 26 and 27, is the greater the far; tlier the layers of the winding are from the plunger, 12, so that the outside layers of the solenoid, 13, are comparatively inefl'ecthe To overcome this, I prefer to choose the dimensions of the solenoid rather small and make the solenoid very compact. But since the solenoid would then be liable to burn out when subjected to the starting current for a considerable length of time, I provide a special fuse, as39, consisting of a v fuse wire inclosed in a thin tube of. insulating material and fastened directly and closely to the solenoid, 13. The dimensions of thefuse wire which, for example, is made of lead, are chosen so that the wire itself will withstand the full current at the start, but will be fused by the additional heat produced in the'so'lenoid, 13, when the latter is kept under current for a longer time.

The design of this special fuse is not difficult, if one makes the fuse Wire of lead, whose melting point is 327 degrees centigrade, and the winding of the solenoid, 13, of an enameled copper wire which will stand without dilficulty or danger a temperature of 110 to 130 degrees centigrade.

Thus one may choose the dimensions of the fuse wire so that this wire itself, on the cold solenoid and with the maximum starting current is subjected to a temperature of about 250 degrees centigrade. The fuse will then melt by the additional heat when the solenoid is heated-to about 80 to 90' degrees centigrade.

When the rectifier is provided with a starting resistance, the fuse wire, 39, may be placed upon a spool of the said resistance.

I claim as my invention:

1. In a vapor rectifier for automatic starting comprising an evacuated container with a plurality of positive electrodes, a mercury cathode and a starting electrode, a solenoid having a plurality of windings forming two groups, one end of the two groups being connected and the point of connection joined to oneof the positive rectifier electrodes, the other end of one group being connected to the positive terminal of the rectifier, the two groups being wound in opposite directions.

2. In a vapor rectifier for automatic starting, the container having a plurality of positive electrodes a negative electrode and a starting electrode, the negative and starting electrodes being out of contact when the container is in its position of rest, a pivoted holder for the container capable of being tilted to permit contact between the negative and the starting electrode, a solenoid provided with a movable iron core linked to the holder of the container, a plurality of windings on said solenoid forming twogroups and electrically connected whereby on applying alternating current voltage to the rectifier, first one group'of the windings is. magnetized, tilting the holder and closing contact between the negative and the starting electrode, and secondly the other winding group is energized, to magnetize the movable iron core and causing the container to drop back to its position of rest.

3. In a system of electrical distribution by means of vapor rectifiers, a rectifier of the said type in combinationwith means for tilting the said rectifier for starting purposes, such means including a solenoid having. two coilsswound in opposite directions and a plunger subject to the influence of said coils, a tilting lever connected to the rectifier and elastically joined to the said plunger.

4. In a system of electrical distribution, a vapor rectifier, tilting means connected therewith, a solenoid for operating the said tilting means, the said solenoid being provided with two coils wound in opposite directions. and a cut out. in the solenoid circuit.

5. A mercury vapor rectifier for automatic starting consisting of an evacuated container with a plurality of positive electrodes, a mercury electrode serving as a cathode, and a starting electrode, a pivoted holder for said container, a laminated iron plunger linked to said holder, a solenoid having coils Wound in the opposite direction for operating said plunger and serving for automatic starting, and an automatic cut out in the circuit of the solenoid.

' 6. A mercury rectifier for automatic start 7 ing consisting of an evacuated container with a plurality of positive electrodes, a mercury electrode serving as a cathode, and a starting electrode, a pivoted holder for said container, a laminated iron plunger linked to said holder, a solenoid having coils wound in opposite directions to operate said plunger and serving for automatic starting, a starting resistance and an automatic cut out in the circuit of the solenoid.

Signed at NeW York in the county of New York and State of New York this 6th day of November A. D. 1912.

JOSEPH C. POLE.

Witnesses:

WM. H. CAPEL, THos. H. BROWN. 

